This invention relates to an electronic timepiece capable of displaying dates and times around the world.
In related art, there are electronic timepieces capable of displaying local time at a current position based on information on an acquired current position or a set position. This allows easy display of exact date and time even when a user does not know the time zone or the daylight-saving time of a place while traveling or the like correctly.
There also are electronic timepieces having a world clock function capable of displaying times around the world in addition to main display of date and time (main clock). Some of such electronic timepieces are provided with a small hour hand and a small minute hand for displaying date and time at another position in addition to a normal hour hand and a normal minute hand or are provided with a digital display screen capable of displaying a sufficient number of digits, so that the date and time at another position can be displayed on a sub clock or a small clock at the same time as the display of a main clock, or some of such electronic timepieces are capable of selectively displaying any of a main clock and sub clocks by switching therebetween with an operation button. Such a world clock function allows the user of an electronic timepiece to quickly know dates and times at multiple places depending on various purposes such as a combination of the time at a current position and the time at another position that is important in business or a combination of the time at a place where a user stays during a trip and the time at a home position where the user has a regular life.
In the related art, however, the date and time of a sub clock are counted and displayed independently of those of a main clock, and the numbers of steps of hands of a sub clock are different from those of a main clock whether the time is displayed in 24-hour display or 12-hour display, which is disadvantageous in that the date and time of the main clock and those of the sub clock need to be modified independently of each other. In contrast, JP 2009-8504 A that is a Japanese patent document, for example, discloses a technology for modifying the date and time (display in minute) of a main clock and modifying the date and time (display in minute) of a sub clock in conjunction with each other.
However, for changing the local time displayed by the sub clock according to a change in the position for the main clock or for replacing the display on the main clock and the display on the sub clock with each other instead of simply modifying the time, the related art is disadvantageous in that the date and time data of the sub clock are not stored in association with position information, which requires manual modification of the sub clock each time in practice or may further result in position information originally set for the main clock being overwritten by different position information.
This invention is directed to an electronic timepiece capable of easily and appropriately changing the local time on a sub clock to that of a desired position in conjunction with changing the local time on a main clock as a result of a change in the current position.